Conventional gear burnishing machines include toothed rotary tools supported in a spaced relationship relative to each other to receive a toothed gear that is rotatably supported on a pair of work spindles about an axis parallel to the axes about which the tools rotate. Driving of one or more of the tools meshes the tool teeth with the gear teeth so that pressure applied therebetween causes the harder teeth of the tools to remove surface defects from the softer gear teeth. Removal of the surface defects on the burnished gears lengthens their useful lifetime and also mitigates gear noise during use.
In order to have high production capacity burnishing machines must include suitable mechanism for loading and unloading gears. The work spindles that rotatably support the gears during the burnishing are conventionally supported for movement so as to perform the loading and unloading of the gears. Automatic conveyors have also been utilized to feed gear burnishing machines and receive burnished gears therefrom after being operated on by the machines.
Conventional apparatus like that described above is disclosed in U.S. Pat. Nos. 1,993,605; 2,736,238; 2,830,712; 2,860,763; 3,315,541; 3,354,782; 3,587,816; 3,590,982; and 3,958,685.
U.S. Pat. No. 4,080,699, which is assigned to the assignee of the present invention, discloses a burnishing machine wherein a pair of elongated gear racks are moved in opposite directions relative to each other with a toothed gear therebetween such that the meshing of the rack and gear teeth provides the sole support for the gear as the gear teeth are burnished by the rack teeth. This machine utilizes a movable gripper mechanism that positions gears to be burnished between the gear racks in a meshing relationship with one of the racks ready for a burnishing cycle.